George l



(No Model.)

G. L. WELLER. METHOD OF SPLITTING ROCK.

No. 475,647. Patented May 24, 1892.

INVEN'II'EIR.

WITNES 5E5 wnuro-uma. vnsnmnmn D 0 UNITED STATES PATENT OFFICE.

GEORGE L. WELLER, OF ELYRIA, OHIO, ASSIGNOR TO PARKS FOSTER AND EUGENE K. MUSSEY, OF SAME PLACE.

METHOD OF SPLITTING ROCK.

SPECIFICATION forming part of Letters Patent N0. 475,647, dated May 24, 1892.

Application filed November 23, 1891. Serial No. 412,848- (No model.)

To all whom it may concern:

Be it known that I, GEORGE L. WELLER, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Ohio, have invented certain new and useful Improvements in Methods of Splitting Rock, of which the following is a specification.

Previous to my invention it has been known that in blasting rock the plane of fracture might be controlled to a great extent by providing the blast hole or holes with angular or V-shaped grooves the points of which lie substantially in the desired plane of fracture. In the practice of this method of splitting rock, however, the blast-holes have been made with concave sides between the angular ends. For example, as shown in Letters Patent No. 357,729, granted February 15, 1887, to T. Murdock, which shows an originally-round hole which is enlarged by the formation of V- shaped grooves at diametrically opposite points therein, and as shown in Letters Patent No. 395,105, granted December 25, 1888, to J. WV. Wykoff, which shows w at are termed ellipticalholeshavingang arends. WVhen a blast is exploded in a hole having one or two concave sides, like those shown in the above-named patents, the force of the blast against any point in the sides of the hole is in a line perpendicular to a tangent to the hole at said point. The sum of these diverging forces acts as wedges, the main tendency of which is to split the rock in a plane which passes through the points of the V-grooves or angular ends of the holes, and it generally happens that the main fracture of the rock will, as it is intended it should, lie in said plane; but the application of the forces in so many different directions often produces sur face cracks of more or less depth and irregularities in the fracture, which it is one of the main objects of my invention to prevent.

My invention consists in drilling, a hole or series of holes in alignment, which holes have angular ends (the points or angles of which lie in the desired plane of fracture) and straight sides which are parallel with and equidistant from said plane of fracture, and then firing a blast in said hole or simultaneously in all of the holes, if there be more than one. \Vhen a blast is exploded in a hole of this description, a part of the force is exerted against the sides of the holes in lines perpendicular theretothat is to say, in directions tending to thrust the two sides of the holes away from 55 each other. The expansion of the blast in the V- grooves produces forces the sums of which act as wedges, tending to split the rock in the plane in which the ends of said grooves lie.

Referring now to the drawings, Figure l is a perspective view of a ledge of rock in which has been made a series of holes of the character described, and Fig. 2 is a top view of a part of said rock having one hole. 65

A A represents the holes, each of which has two parallel sides a a and two angular or V- shaped ends a a. The plane represented by the dotted line which passes through the angle of said ends is parallel to and equidis- 7o tant from the sides 60 a and is therplane in which the rock will be split when a blast is fired in said holes.

\Vhen holes of the above-described character are formed in alignment in the rock to be 75 fractured, as shown, the rock will be split apart in the plane passing through all of the angles and with comparatively few surface cracks and with greater regularity than when the blast-holes are of any other shapes.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The method of splitting rock, which consists in forming in said rock a hole having V- 85 shaped ends and straight sides, which are par allel to each other and to a plane passing through the points of said V-shaped ends, and then firing a blast in said hole, for the purpose specified. 9o

2. The method of splitting rock, which consists in forming in said rock in alignment a series of holes, each having V-shaped ends and sides which are parallel to and equidistant from a plane passing through the points 5 of all of said V-shaped ends, and simultaneously exploding a blast in all of said holes, for the purpose specified.

GEO. L. WELLER.

Witnesses:

H. M. CARPENTER, LIBBIE KROI-IN. 

